Longitudinal Linkage

Linkage workflow, cohort integration logic, and the analytical context connecting childhood trajectories to adolescent outcomes.

Purpose

This page documents the longitudinal linkage stage that combines mental health outcome harmonization and SDoH trajectory information into the final integrated secondary analysis dataset.

Goal Alignment

The linkage workflow directly supports the project objectives:

  1. Build and maintain a linked analysis dataset.
  2. Quantify direct and mediation relationships for depression outcomes.
  3. Characterize social determinant trajectories across childhood windows.

Stage Flow (Current Build Counts)

%%{init: {"flowchart": {"curve": "linear", "htmlLabels": true}} }%%
flowchart LR
  O1["Objective 1<br/>Build linked<br/>analysis dataset"]
  O2["Objective 2<br/>Quantify direct<br/>and mediation links"]
  O3["Objective 3<br/>Characterize SDoH<br/>trajectories"]

  S1["Linkage Stage 1<br/>Psychometric<br/>calibration"]
  S2["Linkage Stage 2<br/>SDoH trajectory<br/>derivation"]
  S3["Linkage Stage 3<br/>Final linkage<br/>and integration"]

  O1 --> S1
  O1 --> S2
  O1 --> S3
  O2 --> S3
  O3 --> S2

  S1 --> A["Psychometric bridge<br/>source data<br/>(n=?)"]
  A --> B["Fit IRT calibration<br/>model (SSQ to PHQ)<br/>reference scale<br/>(n=?)"]
  S1 --> C["SSQ-only cohort<br/>response data<br/>(n=?)"]
  C --> D["Apply calibration<br/>for harmonized<br/>depression endpoint<br/>(n=?)"]
  B --> D

  S2 --> E["Childhood exposure<br/>longitudinal data<br/>(n=?)"]
  E --> F["Derive SDoH<br/>trajectories<br/>0-5 years (n=?)<br/>6-12 years (n=?)<br/>Both (n=?)<br/>Only 0-5 (n=?)<br/>Only 6-12 (n=?)<br/><br/>"]

  S3 --> G["Assemble mental<br/>health component<br/>(n=?)"]
  S3 --> H["Assemble SDoH<br/>trajectory component<br/>(n=?)"]
  D --> G
  F --> H

  G --> I["Integrated secondary<br/>analysis dataset<br/>(n=?)"]
  H --> I

  classDef objective fill:#eef2ff,stroke:#4338ca,color:#1e1b4b,stroke-width:1.5px;
  classDef stage1 fill:#dbeafe,stroke:#1d4ed8,color:#0f172a,stroke-width:1.5px;
  classDef stage2 fill:#fff7ed,stroke:#c2410c,color:#431407,stroke-width:1.5px;
  classDef stage3 fill:#ecfdf5,stroke:#059669,color:#064e3b,stroke-width:1.5px;
  classDef psych fill:#dbeafe,stroke:#1d4ed8,color:#0f172a;
  classDef sdoh fill:#ffedd5,stroke:#c2410c,color:#431407;
  classDef integ fill:#dcfce7,stroke:#059669,color:#064e3b,stroke-width:1.5px;
  class O1,O2,O3 objective;
  class S1 stage1;
  class S2 stage2;
  class S3 stage3;
  class A,B,C,D,G psych;
  class E,F,H sdoh;
  class I integ;

Interpretation

  1. Stage 1 calibrates depression information for SSQ-only records.
  2. Stage 2 derives SDoH trajectory coverage across 0-5 and 6-12 windows.
  3. Stage 3 integrates both streams and keeps participants with both: Depression endpoint and SDoH trajectory coverage.

Completion Criteria

This stage is complete when:

  1. Depression endpoint values are available for integrated mental health records.
  2. SDoH trajectory coverage is available across childhood windows.
  3. Final integrated data retains only participants meeting both criteria.

Notes

  • Counts are distinct participants (USUBJID) and are calculated at render time.
  • Violet nodes: proposal objectives.
  • Blue nodes: psychometric stage.
  • Orange nodes: SDoH trajectory stage.
  • Green nodes: final integration stage.